Table 3.

A comparison of progeny phage output from a M13mp7L2 vector containing [+ta]-B[a]P-N²-dG as determined in E. coli carrying amino acid replacements at the roof-amino acid I38 and/or other sites in UmuC(V)¹

I38	2nd Site	Yield	Protein Level2
wt	wt	100% (16)	100% (3.9)
I38A	wt	19% (4.0)	99% (17)
wt	A39T	22% (2.8)	120% (8.0)
I38A	A39T	60% (16)	104% (25)
wt	V29L	32% (1.0)	72% (11)
I38A	V29L	34% (1.0)	39% (14)
wt	V29I	99% (25)	157% (13)
I38A	V29I	42% (6.0)	126% (13)
wt	V29M	244% (25)	32% (3.0)
I38A	V29M	23% (6.0)	46% (1.0)

¹See footnote ¹ in Table 2; “wt” refers to the wild type amino acid at the indicated position.

²Protein level as determined by Western blotting. Values (in percent) are the average of at least three experiments with standard deviation in parenthesis.